The present invention relates to a sewing machine with electronic stitch pattern control, whereby memories containing control data are interchangeably provided at the sewing machine. Such sewing machines with interchangeable storage units are known but there has not been proposed a solution for providing a simple, safe interchange of the memories and a safe assignment and selection of the desired stitch pattern by operators, such as housewives.
It is known to equip the sewing machine with a separate electronic control module, which module comprises operating elements, more particularly keys for the selection of the desired function of the machine (U.S. Pat. No. 4,055,131). In this case, the objective is to simplify the construction of the sewing machine, and to have the machine operated by a skilled operator but not needing an interchange by the operator. A similar solution is known from U.S. Pat. No. 4,406,235 whereby the modules are in the form of complete panels which may be connected at will with a fundamental execution of the sewing machine. In this case, the connection is done by a cable. Also in this case, one aims at a simplification of the production of different models of sewing machines. An interchange of the module by the owner of the machine or by the operator is not foreseen nor possible.
Similarly, U.S. Pat. No. 4,203,378 shows a sewing machine with an interchangeable storage unit for different stitch patterns. This storage unit consists of an even plate which is inserted in a recess of the case of the machine and covered by a cover. As the storage unit is an integral part of the manufactured machine, an interchange of the storage unit by the operators is not envisaged. It is solely intended, if further development of the machine is desired to adapt only the storage unit but not the whole electronics.
It is also known to provide a slit in the sewing machine for a cartridge containing data for controlling determined programs (U.S. Pat. No. 4,475,784). However, when inserted, the cartridge is not visible at all so that a simple, safe interchange of a desired program at the cartridge connected with the sewing machine is not possible.